Problem: Christopher has walked his dog for a total of $55$ miles since he started walking daily. He has been walking $5$ miles each day. For how many days has Christopher been walking?
The number of days that Christopher has been walking is the total number of miles walked divided by the number of miles walked each day. $55\text{ miles} \div 5\text{ miles per day} = \text{number of days walking}$ $55\text{ miles} \div 5\text{ miles per day} = 11\text{ days}$